Hydrangea root and cranberry juice are good for cleansing the kidneys. They may increase your lower back pain temporarily. For more information, read the book I mentioned in my last post.
Have you done any other colon cleansing? Read "Dr. Jensen's Guide to Better Bowel Care" by Dr. Bernard Jensen to learn about this and its importance. How many colonics have you done? You probably need another one soon. I did several before my liver flush, and one the day after it. The latter released a lot of old toxins that my liver had dumped into my colon during the cleanse.